1. Field of Invention
This invention relates in general to computer and processor architecture, and more particularly, to a method for client workload characterization.
2. Description of Background
A processor's performance can be defined in terms of transactions per unit time, the number of end-users running concurrently. Metrics such as Internal Transaction Rates (ITR), External Transaction Rates (ETR) and Path Length are key indicators of the characteristics of a customer's workload. A processor's absolute capacity can be determined for any specific workload.
The current process to size a zSeries processor's performance uses the IBM Large System Performance Reference (LSPR) methodology: five well-defined workloads are sized to obtain ITR ratio tables of relative performance.
The LSPR ratios represent IBM's assessment of relative processor capacity in an unconstrained environment for specific benchmark workloads and system control programs specified in the tables. Ratios are based on measurements and analysis. The amount of analysis as compared to measurement varies with each processor.
Each individual LSPR workload is designed to focus on a major type of activity, such as interactive, on-line database, or batch. The LSPR does not focus on individual pieces of work such as a specific job or application. Instead, each LSPR workload includes a broad mix of activity related to that workload type.
A wide variety of workload environments exist throughout the world, using any number of different software products. It is highly unlikely that an individual LSPR workload will represent the totality of a particular production workload. Rather, the LSPR workloads are intended to define the envelope (or range) of the expected capacity difference between two processors. As part of a capacity planning exercise for a particular production workload, the intent should be to estimate where in the envelope the production workload will fall by considering a mixture of the LSPR workloads that best represent the production environment.
Thus, there is a need to provide a fact driven, automated validation mechanism into the LSPR process.